The server currently enables SO_KEEPALIVE on sockets whenever it is defined. On Linux it goes the extra mile and attempts to set a reasonable value for TCP_KEEPIDLE and TCP_KEEPINTVL (the default TCP_KEEPIDLE value on Linux - and keep-alive timeout on Windows - is a completely useless 7200 seconds).

The server should attempt to set a reasonable value for TCP_KEEPIDLE and TCP_KEEPINTVL whenever they are defined, not just on Linux. It should also attempt to set the equivalent values on Windows using WSAIoctl.

References:
https://github.com/mongodb/mongo/blob/master/src/mongo/util/net/sock.cpp#L153-L193
http://www.tldp.org/HOWTO/html_single/TCP-Keepalive-HOWTO/#setsockopt
https://msdn.microsoft.com/en-us/library/windows/desktop/dd877220(v=vs.85).aspx